#include<stdio.h>
#include"mymath.h"
#include"mystring.h"

int main()
{
  int x = 100;
  int y = 20;
  printf("x + y = %d\n", Add(x, y));
  printf("x - y = %d\n", Sub(x, y));
  printf("x * y = %d\n", Mul(x, y));
  printf("x / y = %d\n", Div(x, y));

  const char* s = "hello world";
  printf("The length of s is %d\n", Strlen(s));
}
